CUET · PHYSICS · PYQ PAPER 2025
A sample of radioactive nuclei has a half life of 5.5 years. The fraction of sample remaining undecayed after 22 years is
- A 12.5%
- B 25%
- C 93.75%
- D 6.25%
Answer & Solution
Correct Answer
(D) 6.25%
Step-by-step Solution
Detailed explanation
\( n = \frac{t}{T_{1/2}} = \frac{22}{5.5} = 4 \) \( \frac{N}{N_0} = \left(\frac{1}{2}\right)^n = \left(\frac{1}{2}\right)^4 = \frac{1}{16} = 0.0625 \)
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